Gridyakina О. Optical, nonlinear-optical and electric properties of ionic thermotropic liquid crystals and layered glasses of cobalt alkanoates

This work presents the results of experimental studies of structural, electrical, optical and nonlinear-optical properties of ionic thermotropic liquid crystals (ITLC) of cobalt alkanoates. Also smectic glasses of cobalt alkanoates and their multicomponent mixtures were also studied. The structure of cobalt alkanoates homologous series (number of carbon atoms in alkanoate chain n = 7, 9, 11) was obtained. It is shown, that typical for ITLC smectic A packing of molecules preserves also in a glass phase (at room temperature). It is obtained that both ITLC of cobalt decanoate and binary mixture with lead decanoate are weak electrolytes (in the temperature region of mesophase existence). The above mentioned compounds are characterized by the presence of the great anisotropy of bulk a conductance. It is shown that metal cations are dominating charge carriers. Their transport occurs along cation-anion interlayers. The charge mobility and concentration in polydomain samples were determined. It is shown that octahedron is a dominant coordination form of cobalt cations. A considerable increase of absorption in cobalt alkanoates homologous series (from n = 7 to n = 11) is due to decrease of cobalt complexes number and dipole moment of d-d-transitions. A dynamic grating recording was realized and studied in mesomorphic glasses of cobalt alkanoates. Recorded gratings are characterized by high values of nonlinear-optical parameters ( ). A possible mechanism of grating recording in mesomorphic glasses of cobalt alkanoates is proposed. It could be explained by laser induced nonlinear electronic polarization of ?-electrons of cobalt complexes.